The Calaveras fault lies within a low velocity zone (LVZ) 1–2 km wide near Gilroy, California. Accelerographs G06, located in the LVZ 1.2 km from the Calaveras fault, and G07, 4 km from G06, recorded ...both the M 6.2 1984 Morgan Hill and the M 6.9 1989 Loma Prieta earthquakes. Comparison of the ground motions shows that a large 0.6–1.0 Hz velocity pulse observed at G06 during the Morgan Hill event may be amplified by focussing caused by the LVZ. Such amplified waves might be a mappable seismic hazard, and the zone of increased hazard can extend as much as 1.2 km from the surface trace of the fault. Finite‐difference simulations of ground motions in a simplified LVZ model show a zone of amplified motion similar to the observations.
Requires a minimum of technical knowledge and gives an illuminating oversight of the historical developments...with many interesting observations along the way."--Proceedings of the Edinburgh ...Mathematical Society "The lively writing makes this suitable supplementary reading for advanced undergraduates from many disciplines. An extensive and often technical bibliography is included for those who want to go further.
PDF
